DISEASES OF THE HEART. 237 



heard at a short distance away from the animal. It can usually be 

 traced very readily to the exciting cause, which we may be able to 

 avoid or overcome in the future and thereby obviate subsequent 

 attacks. Rest, a mild stimulant, or a dose or two of tincture of digi- 

 talis or opium will generally give prompt relief. When it is due to 

 organic impairment of the heart it must be regarded as a symptom, 

 not as a matter of primary specific treatment. 



SYNCOPE, OR FAINTING. 



Actual fainting rarely occurs among horses. It may, however, be 

 induced by a rapid and great loss of blood, pain of great intensity, a 

 mechanical interference with the circulation of the brain, etc. 



Symptoms. — Syncope is characterized by a decrease or temporary 

 suspension of the action of the heart and respiration, Avith partial or 

 total loss of consciousness. It generally occurs suddenly, though 

 there may be premonitory symptoms, as giddiness, or vertigo, dilated 

 pupil, staggering, blanching of the visible mucous membranes, a rap- 

 idly sinking pulse, and dropping to the gi'ound. The pulse is feeble 

 or cea.ses to beat ; the surface of the body turns cold ; breathing is 

 scarcely to be perceived, and the animal may be entirely unconscious. 

 This state is uncertain in duration — generally it lasts only a few 

 minutes; the circulation becomes restored, breathing becomes more 

 distinct, and consciousness and muscular strength return. In cases 

 attended with much hemorrhage or organic disease of the heart, the 

 fainting fit may be fatal; otherwise it Avill prove but a transient 

 occurrence. In paralysis of the heart the symptoms may be exactly 

 similar to syncope. Syncope may be distinguished from apoplexy by 

 the absence of stertorous breathing and lividity of the visible mucous 

 membranes. 



Treatment. — Dash cold water on the head; administer a stimu- 

 lant — 4 ounces of whisky or half an ounce of carbonate of ammonia. 

 Prevent the animal from getting uj) too soon, or the attack may 

 irnmediately recur. Afterwards, if the attack was due to weakness 

 from loss of blood, impoverished blood, or associated with debility, 

 general tonics, rest, and nourishing food are indicated. 



HYPERTROPHY OF THE HEART, OR CARDIAC ENLARGEMENT. 



Hypertrophy of the heart implies augmentation of bulk in its 

 muscular substance, with or without dilatation or contraction of its 

 cavities. It may exist with or without other cardiac affections. In 

 valvular disease or valvular insufficiency hypertrophy frequently re- 

 sults as a consequence of increased demand for propelling power. 

 The difficulties with which it is most frequently connected are dilata- 

 tion and ossification of the valves. It may also occur in connection 

 with atrophied kidneys, weak heart, etc. It may be caused by an 

 increased determination of blood to the organ or from a latent form 



